SQL> CREATE TABLE t_value(
CON> i INTEGER PRIMARY KEY,
CON> n INTEGER  DEFAULT 1 CONSTRAINT check_n_00 CHECK (VALUE > 0)
CON> );
Statement failed, SQLSTATE = 42000
unsuccessful metadata update
-CREATE TABLE T_VALUE failed
-Dynamic SQL Error
-SQL error code = -901
-Illegal use of keyword VALUE
SQL>

...
CURRENCY CHAR(3) NOT NULL
CONSTRAINT CHECK_CURRENCY
CHECK (VALUE IN ('AUD','EUR','GBP','RUR','USD','YEN')),
...